diff --git a/src/adc/adcconst.h b/src/adc/adcconst.h
index fc556ba..c4c5c8d 100644
--- a/src/adc/adcconst.h
+++ b/src/adc/adcconst.h
@@ -33,7 +33,7 @@ typedef uint32_t fourcc_t;
 #define FOURCC(a,b,c,d) (fourcc_t) ((a << 24) | (b << 16) | (c << 8) | d)
 
 /* default welcome protocol support message, as sent by this server */
-#define ADC_PROTO_SUPPORT "ADBASE ADTIGR ADPING"
+#define ADC_PROTO_SUPPORT "ADBASE ADTIGR ADPING ADUCMD"
 
 /* Server sent commands */
 #define ADC_CMD_ISID FOURCC('I','S','I','D')
@@ -93,6 +93,15 @@ typedef uint32_t fourcc_t;
 /* Extension messages */
 #define ADC_CMD_HCHK FOURCC('H','C','H','K')
 
+/* UCMD Extension */
+#define ADC_CMD_BCMD FOURCC('B','C','M','D')
+#define ADC_CMD_DCMD FOURCC('D','C','M','D')
+#define ADC_CMD_ECMD FOURCC('E','C','M','D')
+#define ADC_CMD_FCMD FOURCC('F','C','M','D')
+#define ADC_CMD_HCMD FOURCC('H','C','M','D')
+#define ADC_CMD_ICMD FOURCC('I','C','M','D')
+
+
 #define ADC_INF_FLAG_IPV4_ADDR          "I4" /* ipv4 address */
 #define ADC_INF_FLAG_IPV6_ADDR          "I6" /* ipv6 address */
 #define ADC_INF_FLAG_IPV4_UDP_PORT      "U4" /* port number */
diff --git a/src/core/hub.c b/src/core/hub.c
index bc18ad5..8697f96 100644
--- a/src/core/hub.c
+++ b/src/core/hub.c
@@ -129,6 +129,14 @@ int hub_handle_message(struct hub_info* hub, struct hub_user* u, const char* lin
 				CHECK_FLOOD(connect, 1);
 				ROUTE_MSG;
 
+			case ADC_CMD_BCMD:
+			case ADC_CMD_DCMD:
+			case ADC_CMD_ECMD:
+			case ADC_CMD_FCMD:
+			case ADC_CMD_HCMD:
+				CHECK_FLOOD(extras, 1);
+				break;
+
 			default:
 				CHECK_FLOOD(extras, 1);
 				ROUTE_MSG;